Modern mailing systems include different machines and operations for printing, organizing, collating, and folding mail materials, sheets, or other documents. These operations are followed by processes for inserting the finalized documents into envelopes. The documents are usually prepared for insertion by processing material in folding machines that use a tool or other mechanical pressure to create a sharply defined crease into a sheet of flexible substrate material, such as the paper or paper sets forming the document, using either a knife folding or buckle folding operation.
For example, commonly assigned U.S. patent application Ser. No. 13/972,972 filed on Aug. 22, 2013, the disclosure which is hereby incorporated by reference in its entirety, discloses a folding machine as combined knife and buckle folders to allow high speed folding of more than one sheet of flexible substrate material into a page set. After folding and forming the sheets of material as a document to be inserted within an envelope, the documents are further processed through a document insertion machine that inserts the documents into envelopes. Some document insertion machines perform some collating and similar processes. Different types of document insertion machines may be used, including the early “Phillipsburg-type” machine that includes picking stations having a respective stack of sheets or other mail inserts and a picker arm that grips a sheet to be inserted into an envelope.
In one exemplary document insertion machine, a stream of open envelopes are conveyed by a conveyor past an inserter arm while individual inserts as documents are retrieved from insert hoppers and added to form a final document. The same or another inserter arm inserts or “stuffs” each packet of mail materials forming the document into an open envelope by pushing the document with pusher members or “fingers.” Once the document is inserted, an envelope is conveyed to an envelope sealing station where the flap covering the envelope opening is sealed shut. Some document insertion machines hold an envelope open using suction cups or other vacuum draw, while other machines blow air into the envelope to open the envelope. Some document insertion machines use suction cups in combination with a vacuum draw to hold an envelope open and create a pocket for insertion of the document. Applying vacuum or suction cups is a slow technique and sometimes dust or other contaminants may enter the machine and interfere with the vacuum or suction. Often these types of document insertion machines and related processing equipment will jam under high speed operation.
Another technical drawback is typically the envelope is fed with the flap over the envelope opening and oriented downward in a standard letter or envelope configuration. The envelope is then moved horizontally or vertically, making document insertion difficult. Also, many of these systems are limited in speed and efficiency.